Giant magnetoresistance of perpendicular magnetic Co/Au multilayers

Co/Au multilayers have been prepared on glass substrates by electron-beam evaporation techniques. The perpendicular anisotropy is induced when the Co layer thickness is less than 12 Å and its origin is discussed phenomenologically. In the perpendicular magnetic multilayers, large giant magnetoresistance appears and it consists of hysteretic and nonhysteretic components. The occurrence mechanism of these components has been discussed and it is suggested that the former arises from antiparallel spin alignment between adjacent Co layers due to the random wall position layer by layer, and the later is related to the granular-type giant magnetoresistance.